Vampire Wire AI-II with 800/CB RCAs

Anyone ever use these ICs? Can you describe their sound and/or compare to others (i.e. Kimber Hero)? On paper they seem like they'd be very good: OCC Copper; twin axial multi-guage stranded; PEF dialectric; 50 pF/m capacitance; copper-based direct gold plated RCAs; $259 1m pair.